Another non-trad here. I came from an engineering background, and knew I would need (1) to take the MCAT and (2) take all of the pre-reqs that engineering did not cover (which was limited to general chem I/II and physics I/II about ten years prior).
For timing reasons, I did not want to take the courses, take the MCAT, and then apply the next year - that is two years of waiting from the time I made the decision (about mid June) and I figured I could crunch that down to one.
So I read that big Kaplan review book in July, took the MCAT in August, and then started pre-req courses (bio I/II, biochem, organic chem, and added A&P, comparative A, genetics, micro etc. since I had the time). Managed to pull a low 30's so I was pretty satisfied.